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yEIJEOTRIG ARG LAMB. No. 281,891`. "Patented Julyll, 1883.I

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. B'LEGTRIG ARG LAMP..

l No. 281,891. Patented July 24, 1883A.

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UNITED STATES' vPATENT OFFICE.

.JOHN LEA, LONDON, COUNTY OF MIDDLESEX, ENGLAND.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 281,891-, dated July 24, 1883.

Application filed May 25, 1882.

T all whom t may concern:

Be it known that I, JOHN LEA, a subject of I-Ier Majesty the Queen of Great Britain, residing at London, in the county of Middlesex,

England, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

My invention has for its object the better regulation of the feed of the carbon or carbons, in order to insure a steady light, and at the same time to employ carbons of great length, so .that what is known as a single lamp 7 ,-that is, one pair of carbons acted upon by one set of feeding 4apparatus-shall burn for a long time without attention. I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a front elevation, and Fig. 2 a side elevation, of my improved electric-arc lamp. Fig. 3 is a plan view of the lamp with some ofthe parts removed to show the circuitconnections more clearly; and Eig. 4 is a diagram of the circuit-connections, the path of the current through the electrodes and solenoid W being indicated by arrows in full lines, and through the magnet M by arrows in dotted lines when the resistance at the arc is normal.

According to my invention, the upper carbon is held in position by rollers a ccf c2, (by preference three,) two of which, c and c, are mounted in a metall frame, A, which frame also carries-a frame, b, in which is mounted the third roller, ci. This third roller is a riding or 35 jockey roller, adjustable to any given pressure by means of the springs c, adjusting-screw c, and thumb-nut c2, the spring being attached to the frame of the jockey-roller at ci. This jockey-roller, as shown in the drawings, is in the position it would occupy if a carbon of large diameter, (as represented by the dotted lines)-say three-fourths of an inch-rbc placed in the lamp between the riding or jockey roller c2 on the one side andthe two rollers c c on the othernside. Should a carbon of smaller diameter be placed in the lamp, the jockey-roller would close upon it by the action ofthe spring c, and by means of the nut c2 sufiicient tension can be put upon it to prevent l 5o its weight revolving the three rollers and allowing the carbon to fall through by gravitation. The rollerc is of larger diameter than (No model.)

carbon as it is consumed is as follows: A solenoid, M, or an electro-magnet is employed, and actuates a gripping-lever, d, for the purpose of revolving the rollers, and this solenoid or electro-magnet is connected as a shunt from the main circuit. This shuntcircuit is divided, to allow of a variable resistance, by being wound differentially or in two parts. When the first part of the wire is wound on, a wire, m, is attached and is brought out of the coil, and then attached to a metal block, e, to which is fastened .a spring, f. The second part of the wire, me', is then wound on, but in the opposite section, and its end brought out and attached to the metal base-plate at i or this second wire may be placed in the lamp as a p resistance-coil, and a branch wire from the connection run up to the spring, attached to it at one end, and the other end of this resistance-coil attached to the base-plate.

M is the core of the feedingsolenoid. The metal block e, to which is fastened the spring f, is placed upon an adjusting-screw, g, passing through a block of insulating material, h, so

that by turning the screw g the spring j' can be lowered, as required. Upon the end of this spring is a platinum piece, j, and another platinum piece, j', on the gripping-lever d, to form contact to out out the resistance-coil or second wire upon the lsolenoid or electro-mag net. The gripping-lever d is suspended at its outer extremity by a spiral spring, 7c, and an adj usting-screw, 7c', which latter passes through the angle-piece B, secured to the top of the frame A'. The other end of this gripping-lever is jointed upon two arms, s s', which are connected to the frame A on each side of the IOO spiral spring w, :uljusting-screw w', grippinglever (l, and arbor much the same as on the feeding side.

'B is a bent arm carrying set-screws t i', against which the arms .5^ si rest, allowing the spiral springs k and w to j ust pull the grippinglevers d d oli' the periphery of the roller a. A piece of iron, S, is placed at the bottom of the arc-making solenoid, and is held fast therein by being screwed into the base-plate. This piece S serves as a magnet to attract and hold down the core N ofthe solenoid WT, which core is attached to the gripping-lever d. On the are-making side is an arm or lever, a', bent into the position shown in Fig. 2 and iixed to the axis (Z3 of the gripping-lever d, so that when the iron core N of the solenoid XV is drawn into the coil this arm or lever presses against the side or' the frame A, and by so doing releases the gripping-lever from the roller a. An upwardly-projecting arm, I), is placed upon the frame of the jockey-roller and is furnished with a pin or stud, p, which is so arranged thereon as to be caught bythe feedinglever d should the cai-bons be apart, and to act upon and release the jockey-roller and allow the upper carbon to descend by gravity and come into contact with the lower carbon. A short-circuiting arrangement is also placed upon the frame of the jockey-roller, so that when the upper carbon is consumed, or if by accident the carbon should break, contact is made at y upon the insulated stud ;1/, which is in connection with the; g (negative) terminal, and as the (positive) terminal is in connection with the frame A, short circuit is made and the lamp cut out. Il' the upper carbon should be consumed until the top oi'such earbon descends below the roller a, then by the pressure caused by the spring c the upper carbon will be displaced, the ]`oekeyroller will be drawn inward, and the long` arm Y will come in contact at y.

fl/X is a copper wire, making good connection for short circuiting. The wire connecting the short-circuiting stud y to the terminal may be of the same resistance as the are, it' required, so that the resistance of the line will remain the same if part ofthe circuit be turned oil".

Of course it will be understood that electromagnets will answer the same purpose as the solenoids by using armatures or keepers in place oi" the iron cores. 4

My improved construction of lamp may be used either with direct currents or with alternating currents. If alternating currents be used, I then prefer to employ a bundle of iron wires in place of iron tubes or solid iron cores.

The action ol" the lamp is as follows: XV hen to be lighted, and should the carbons be apart, th e current enters at the positive terminal, and, traversing the shunt-coil M, pulls down the core M until the gripping-lever d comes against the stud p on the arm I, and, displacing the j ockey-roller, causes the upper carbon to come into contact with the lower carbon. The current then passing by the tl rick-wire solenoid XV,

the core ofthe shunt-coil is drawn back by the spring L, having lost its power bythe current passing in the thick wire and through the carbons andare. The core N is brought down upon the piece of iron S, the arm x displaces the gripping-lever d after turning the roller n. in the proper direction, this being in the direction to raise the upper carbon 'lromthelower one, forming an are between them. The core N remains down all the time the lamp is alight. As the are becomes longer by the carbons being consumed, so more current passes by the shunt-coil, passing into it from the frame-work A through S and d to platinum contact y", at this time touching platinum eontactj, up the spiral spring f to the block oi' metal c, through the wire m into the coil, and through the inner halt ol' the coil out ofthe inside end ofthe coil M to the negative terminal, or to the tl1ick-wire coil end, which is the same thing. This increase ol' current through this shunt-coil, which is the inner half of coil M, causes the iron M/, suspended to gripping-lever d and spiral spring 7c, to be drawn into the solenoid-coil M very slowly, which turns the roller a and feeds the upper carbon down until the two platinum contacts be parted. Thus, as the current cannot pass by the gripping-lever d it has consequently to pass by m from the base-plate, instead of at the frame-work A. Now, it will be seen that the shunt-coil has to conduct the current through the whole of its wire from the base-plate at m out of its inside end to negative. Thus it has a much greater resistance to pass through, which causes it to exert much less attractive force upon the iron M, and allows the spiral spring k to pull it up out of the coil M until it again makes contact between the two platinum pieces j and j, when the outer half or part of the coil M is again short-cireuited, and the current passes again by thc gripping-lever l through the frame A, as before. Now, it' the arc is still of a greater length than required, this extra attractive force again pulls down the iron m and again breaks at j and .7', and so on, continues the up-and-down motion until the are is its proper length, when the up-and-down motion ceases until the are is again longer by the carbons being consumed, which means greater resistance in the arc, and causes more current to ilow again bythe shuntcoil, which again does its work, as before.

I amaware that the upper electrode in an arc-lamp hasbeen guided and sustained by two rollers at opposite sides of the electrode, one roller being in bearings in a stationary frame and the other roller upon alever provided wi th a spring to give the desired pressure upon the electrode, and I am aware thatamagnet oi'low resistance in the lamp-circuit and a magnet of high resistance in a shunt-circuit have been employed for regulating the feed of the upper carbon.

I-Iaving fully described my invention, what I desire to claim, and secure by Letters Patent, is

l. In an electric-arc lamp, the rollers a c in.

IOO

IIO

a stationary frame at one side ofthe electrode, the intermediate roller, a2, in a swinging frame at the other side of the electrode, and a spring and adj listing-screw for regulating the pressure of the roller a2. upon the electrode, in combination with means for turning the roller a, substantially as and for the purposes specified.

2. The swinging frame s, gripping-lever d,

. and its spring and stop, in combination with AIO stop, in combination with the rollers a a?, electrodes, and means for actuating said grippinglevers, substantially as and for the purposes specified. I

5. The roller lever-arm Y, and its spring,

and. rollers ce a', inthe stationary frame, in combination with the carbon electrodes, the stationary contact y, and circuit-connections, as specified, so that when the upper end oi the electrode passes below the roller the leverg/ is thrown by its spring in contact with y and closes a circuit between the and connections to the lamp, substantially as and for the purposes specified. 6. The combination, with the rollers c a2, gripping-levers d d, and electrodes, .of the magnet W, of low resistance in the main circuit, the magnet M, with a two-part coil or" high resistance in a shunt-circuit, and circuit-connec tions, arranged substantially as and for' the purposes specified. u

In testimony whereof I haveset my hand, in the presence of two subscribing witnesses, this Sth day of May, 1882.

JoHN LEA. [n s] Vitnesses:

ERNns'r DE PAss,

68 Fleet Street, London. JOHN DEAN,

17 Gmcechurci Si., London. 

